Largest eyes give squid a big advantage

Get an eyeful of these peepers. They are the lenses from the eyes of a colossal squid (Mesonychoteuthis hamiltoni), the largest known invertebrate. Complete squid eyes can reach 27 centimetres across, making them the largest eyes in the animal kingdom.

They may help colossal squid spot sperm whales, their only predators. Sperm whales hunt the squid in the deep ocean, over 600 metres beneath the surface, probably relying on echolocation.

Based on the size of the squid's pupil, Dan-Eric Nilsson of Lund University in Sweden estimates that it could detect approaching whales from over 120 metres, giving it plenty of time to take evasive action.